1. Field of the Invention
The present general inventive concept relates to test equipment to test a semiconductor device, and more particularly, to a probe card by which transmission can be performed at a high speed by improving a transmission characteristic of a signal transmitted from a test apparatus, thereby reducing manufacturing costs by manufacturing the probe card in a replacement type or a separation type.
2. Description of the Related Art
To fabricate a conventional semiconductor chip, a series of processes, such as an oxidation process, a diffusion process, an ion implantation process, a photo-etching process, and a metal process, which are all performed on a wafer, are required. Between the series of processes and a packaging process for packaging semiconductor chips fabricated on the wafer, a probing test process is performed to test whether each semiconductor chip has a normal electrical characteristic.
A probe card is mainly used as probing equipment to test a wafer on which semiconductor chips are fabricated. That is, by connecting probe tips equipped at one end of the probe card to electrode pads of each semiconductor chip, applying a predetermined electrical signal to the semiconductor chip, and receiving an electrical signal output from the semiconductor chip, a normal or abnormal state of each semiconductor chip implemented on a semiconductor substrate is tested.
FIG. 1 is a cross-sectional diagram of a conventional probe card 100.
Referring to FIG. 1, the conventional probe card 100 includes a Printed Circuit Board (PCB) 110, a connector 120 assembled with the upper surface of the PCB 110 in order to be connected to test equipment (not illustrated), wires 130 electrically connected between the connector 120 and probe needles 160, needle supporters 140 for supporting the probe needles 160, epoxy resins 150 for preventing the movement of the wires 130 and the probe needles 160, and the probe needles 160 connected to electrode pads of a semiconductor chip.
The PCB 110 is formed in a disc shape and has an electrical wiring pattern therein. In the central portion of the PCB 110, a hole may be formed to expose a wafer. The connector 120 is a part used to connect test equipment, such as a T5592, which is a type of Auto Test Equipment (ATE), to the PCB 110, and may be a Zero Insertion Force (ZIF) socket or a pogo pin. The wires 130 are connected to the connector 120 via the electrical wiring pattern formed inside the PCB 110, and may be made of copper or a copper alloy.
The needle supporters 140 are members for supporting the probe needles 160 when the probe needles 160 are contact with electrode pads of a semiconductor chip, and may be made of ceramics. The epoxy resins 150 are used to attach the wires 130 to the probe needles 160 and prevent the movement of the probe needles 160 when a semiconductor chip is tested. The probe needles 160 are members contacted with electrode pads of a semiconductor chip and are formed to have sharp ends due to chemical etching. The probe needles 160 can be made of a material, such as tungsten, and may be bent at a predetermined angle.
The conventional probe card 100 transfers an electrical signal input from test equipment (not illustrated) to the probe needles 160 via the wires 130 when the conventional probe card 100 tests a semiconductor component, such as a memory or a controller. However, this method causes difficulty in testing at a high speed. For example, since a corner frequency (3 dB) is observed below 600 MHz, if an electrical signal is transmitted at a frequency of more than 1 GHz, a signal transmission characteristic is rapidly decreased at a connection part of the probe needles 160.
In addition, since the conventional probe card 100 has a structure in which the PCB 110 and the needle supports 140 are in one body, when semiconductor chips having different positions or numbers of pads are tested, it is inconvenient for the entire probe card 100 to require replacement. In addition, when the probe needles 160 become abnormal, it is difficult to replace or repair the probe needles 160. In particular, since the probe card 100 is expensive, when the probe card 100 is out of order or becomes abnormal, expenses required to replace or repair the probe card 100 become high.